An information sharing method includes that a first redundancy device generates a first supervision frame that includes device information of the first redundancy device, where the first supervision frame detects whether a second redundancy device on a transmission link on which the first redundancy device is located in the redundancy network is in a working state, where the first redundancy device is any redundancy device in the redundancy network; and where the first redundancy device sends the first supervision frame to the second redundancy device in a multicast manner. The device information of the redundancy device is carried in the supervision frame.